Technical Field
The present invention relates to an information processing device in which operation input is carried out by way of a touch panel, a method for controlling the information processing device, and a program.
Background Art
In recent years, information processing devices such as smartphones and portable game devices are frequently equipped with a display unit and a touch panel that are arranged overlapping the display unit that detects contact by an indication means such as a finger or a stylus pen, the operation input being carried out by way of the touch panel.
In an information processing device in which operation input is carried out by way of a touch panel, an operation image that includes operation buttons that indicate operation content is displayed on the display unit, and by placing the indication means in contact with an operation button, processing that corresponds to the operation content that is indicated by the operation button is carried out. Operation input by way of a touch panel not only allows the user to carry out operation input intuitively, thereby improving usability, but further allows the elimination of a physical key construction for operation input from the information processing device, thereby allowing an increase of the size of the display unit that corresponds to the eliminated key construction.
However, when the information processing device is a portable device such as a smartphone that can be carried by the user, since portability is important, the size of the display unit is limited to a size that can be accommodated in the palm of the user's hand. When an entire operation image is to be displayed under limitations that are imposed on the size of the display unit, the display of the operation buttons will be excessively reduced in size, and as a result, there is possibility that the selection of the operation buttons becomes difficult.
Patent Document 1 (JP2003-330613A) and Patent Document 2 (JP2010-204781A) disclose information processing devices in which the area of a portion of the operation image is displayed on the display unit, and when the indication means has been placed in contact with the touch panel and a drag operation is carried out in which the contact point is caused to slide, the display of the display unit is scrolled in accompaniment with the drag operation in the same direction as the direction of movement of the contact point and by an amount that corresponds to the amount of movement of the contact point. By means of these information processing devices, displaying only the area of a portion of the operation image on the display unit can prevent excessive reduction of the size of the display of the operation buttons, and further, when a target operation button is not displayed on the display unit, can realize display of the target operation button by scrolling the display of the display unit.